The disclosure of Japanese Patent Application No. 2001-338094 filed on Nov. 2, 2001 including the specification, drawings and abstract is incorporated herein by reference in its entirety.
1. Field of the Invention
The present invention relates to a monitor system of vehicle outside for detecting a distance between a vehicle and a three-dimensional object existing in front of the vehicle based on information from an image and an information derived from a laser radar, and to method of monitoring of vehicle outside.
2. Description of the Related Art
Recently, technologies relating to an advanced safety vehicle (ASV) have been positively developed and some of the technologies have been in practical use. The advanced safety vehicle includes a TV camera, a laser radar, and like mounted thereon, detects preceding vehicles and obstructs, determines a degree of danger of collision therewith, and gives an alarm to a driver. And the vehicle is stopped by being automatically applied with a brake or automatically increases or decreases its running speed so as to keep a safe distance between the vehicle and a preceding vehicle.
Incidentally, when a distant three-dimensional object is recognized in these technologies by coordinating the distance data obtained by an image from cameras with the distance data from a laser radar, there is a possibility that a single object is erroneously recognized as a plurality of different objects. The measurement errors in the image and the laser radar are caused by the difference between the characteristics of the distance data obtained by the image and the characteristics of the distance data obtained by the laser radar. For example, when the distance of a distant preceding vehicle is detected by the laser radar, the laser radar mainly detects the reflectors of the vehicle. On the contrary, the distance of the vehicle detected by the image has a large measurement error, and the vehicle may be detected as if there is a three-dimensional object at a farther position. When the difference between the distance data obtained by the image and the distance data obtained by the laser radar is increased as described above, a single three-dimensional object is calculated as if it is a plurality of three-dimensional objects, from which a problem is arisen in that an unnecessarily long calculation time is required.
An object of the present invention, which was made in view of circumstances described above, is to provide a monitor system of vehicle outside capable of promptly and accurately recognizing a three-dimensional object existing in front of the vehicle based on the information from an image and the information from a laser radar without executing unnecessary processing, and to provide a method of monitoring of a vehicle outside.
The monitor system of vehicle outside includes image-measured distance detection means for detecting the distance data between the vehicle and a three-dimensional object existing in front of the vehicle based on the information of an image in front of the vehicle, laser-measured distance detection means for detecting the distance data between the vehicle and the three-dimensional object existing in front of the vehicle based on the information of a laser radar for projecting a laser beam from the vehicle. Further, the monitor system includes three-dimensional object recognition means for recognizing the three-dimensional object existing in front of the vehicle based on the distance data detected by the image-measured distance detection means and the distance data detected by the laser-measured distance detection means.
With this arrangement, the three-dimensional object recognition means coordinates the distance data detected by the image-measured distance detection means with the distance data detected by the laser-measured distance detection means. The two sets of the distance data existing in a horizontal direction and detected by the laser-measured distance detection means have a width within a preset value and the difference between the distance values of the two sets of the distance data is within a preset distance value. Under the above conditions, the three-dimensional object recognition means recognizes the three-dimensional object by making the distance data, which exist between the two sets of distance data at the positions farther than the positions of the two sets of the distance data by a predetermined distance and which are detected by the image-measured distance detection means ineffective.
The above and other objects, features and advantages of the present invention will become more clearly understood from the following description by referring to the accompanying drawings.